Excitability in the host-pathogen interactions of HIV infection and emergence of viral load blips.

HIV viral blips are characterized by intermittent episodes of detectable low-level viraemia which return spontaneously to an undetectable level in patients with full suppression of viraemia (<50 copies/ml). The precise mechanisms responsible for viraemia blips and their clinical significance are not known. In this work, we analyze HIV blips using a mathematical model describing basic host-pathogen interactions, in particular regulatory processes involving CD4+, CD8+ T-cells and the virus.